Front Range
AvalancheJoe Ambrosich · Jan 2, 2015 · Front Range
Weather
North, east and south facing slopes surrounding arapahoe lakes had increasing wind throughout the day. The wind direction was north east and wind was more intense further up in elevation. Windy elevations ranged from 11000 to 12000 feet. Day was mostly sunny.
Snowpack
A pit was dug around 11400 feet just north of arapahoe lakes on a south facing aspect. There were two main layers observed. The first layer was 20 cm from the surface and was likely formed by the most recent storm. The second layer was 75 cm from the surface. An isolated block test was performed and the first layer sheared cleanly after 6 blows on a shovel from the elbow. The lower layer sheared cleanly but only after harsh full blows using the entire shovel handle length. The upper layer was the primary concern however the lower layer was also a concern due to propagation if the upper layer was triggered. Wind loading had also become an issue on north and east slopes throughout the day.
Avalanche
Several large natural slides were observed. The largest and most recent was likely only a day or two old and was on a north east aspect above arapahoe lakes. The slide appeared to be into the second layer around 75 cm deep, a hundred feet wide and ran the length of the pitch from around 11800 ft to about 11300 ft. This slide was not immediately visible from the base of the bowl. Only after partially gaining the ridge north of arapahoe lakes was it fully visible. A second large slide was observed on the east aspect again around 11800 feet. This slide was only as deep as the top layer and wind loading as well as cliffs below the slide contributed to the instability. Debris from the newest avalanche as well as the older one was clearly visible. We concluded that the rating of moderate danger did not apply to this specific area. From the observations more caution is necessary.